adenosine 5'-monophosphoramidase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: adenosine 5'-monophosphoramidate + H2O = AMP + NH4+. Other substrates include AMP-morpholidate, AMP-N-alanine methyl ester and AMP-alpha-acetyl lysine methyl ester. [PMID:11805111, RHEA:67916]

Adenosine 5'-monophosphoramidase activity refers to the catalytic hydrolysis of adenosine 5'-monophosphate (AMP) to adenosine and inorganic phosphate. This enzymatic activity is crucial for regulating cellular levels of AMP, a critical signaling molecule involved in diverse cellular processes. The enzyme responsible for this activity, AMPase, is broadly classified as a phosphohydrolase, specifically targeting the phosphodiester bond connecting the phosphate group to the 5' carbon of the ribose sugar in AMP.

The precise molecular mechanism of AMPase involves the following steps:

1. **Binding of AMP:** AMP binds to the active site of the enzyme, typically through interactions with amino acid residues that form a specific binding pocket.
2. **Nucleophilic attack:** A nucleophile, often a hydroxide ion (OH-), present in the active site, attacks the phosphorus atom in the phosphate group of AMP.
3. **Cleavage of the phosphodiester bond:** The attack of the nucleophile leads to the breaking of the phosphodiester bond between the phosphate group and the 5' carbon of ribose.
4. **Release of products:** The products of the reaction, adenosine and inorganic phosphate, are released from the active site, allowing the enzyme to bind another AMP molecule.

AMPase activity plays a significant role in various cellular functions, including:

* **Purine nucleotide metabolism:** By hydrolyzing AMP, AMPase regulates the levels of AMP, a key intermediate in purine nucleotide biosynthesis and degradation pathways.
* **Signal transduction:** AMP acts as a signaling molecule, participating in various cellular processes such as energy metabolism, cell growth, and differentiation. AMPase modulates these processes by controlling AMP levels.
* **Phosphate homeostasis:** AMPase contributes to phosphate homeostasis by hydrolyzing AMP, thereby releasing inorganic phosphate.
* **Cellular detoxification:** AMPase may participate in detoxification by removing AMP from the cell, which can be harmful if accumulated in high concentrations.

The specific function and regulation of AMPase vary depending on the organism, tissue, and cellular context. Mutations or dysregulation of AMPase activity can lead to various metabolic disorders, highlighting its importance in maintaining cellular function and homeostasis.'
"

Proteins (2)

Compounds (3)